Effect of castration on rabbits housed in littermate pairs.

Conventional solitary caging for research rabbits precludes many postural and social behaviors. Several studies that have investigated enrichment strategies for rabbit does have found intact males usually too aggressive for paired or group housing. This study investigated the possibilities that male siblings will remain compatible if never separated from birth and that castration will improve compatibility among young sibling male rabbits. As a side benefit of pair housing for all rabbits, the larger cages (modified dog cages) allowed rest and other postures not possible in conventional single cages. In addition, there was no evidence of the stereotypies observed among individually housed rabbits. Castrated, post-weanling, male, Flemish Giant x Giant Chinchilla rabbit littermates demonstrated a significantly higher level of living together compatibly than did the intact controls. All rabbits chose to rest in close proximity or contact, although this preference was stronger in castrated males. During puberty, intact males displayed more serious aggression. We conclude that young adult littermate rabbits can live compatibly as pairs and that castration improves compatibility among males. Paired rabbits exhibit many postures and behaviors that are not possible in the small, solitary cages currently listed as minimum recommendations.

Proteinuric hypertension in a pregnant baboon: was this pre-eclampsia?

We report the results of investigating a pregnant baboon that developed hypertension, proteinuria, and oedema in late gestation. Although the clinical presentation suggested a diagnosis of pre-eclampsia, the evolution of her clinical signs and results of a renal biopsy performed 3 weeks after delivery suggested that glomerulonephritis was the underlying disease.

A cytotoxicity assay for Clostridium spiroforme enterotoxin in cecal fluid of rabbits.

Clostridium spiroforme enterotoxin-mediated diarrhea can be a common cause of mortality among weanling age rabbits. Definitive diagnosis of this disorder requires detection of the causative enterotoxin. Using filtered cecal supernatant from necropsy specimens, antibodies to C. spiroforme and its products and Vero cells, a cytotoxicity assay was performed on 22 rabbits with clinical signs and lesions consistent with C. spiroforme enterotoxin-mediated diarrhea. A cytotoxic effect was detected, generally within 4 h, in 18 of 22 rabbits. The cytotoxic effect was blocked by preincubation of the cecal material with antibodies to C. spiroforme and its products. Culture of cecal contents and smears of cecal contents identified C. spiroforme in 10/22 and 12/22 cases, respectively. This cytotoxicity assay provided a rapid and sensitive method for diagnosing C. spiroforme enterotoxin-mediated diarrhea.

Treatment of experimentally induced trichinosis in dogs and cats.

Studies were undertaken to determine the efficacy of milbemycin oxime against the enteric adult stages of Trichinella spiralis and of albendazole against the muscle stage larvae in experimentally infected dogs and cats. Specific-pathogen-free Beagle pups (n = 6) and domestic shorthair kittens (n = 6) were inoculated with 7,500 first-stage larvae of Trichinella spiralis. Physical examination (including collection of blood and fecal samples) was performed weekly. During the first week after inoculation, all animals had mild gastrointestinal tract disturbances, but stages of T spiralis were not observed in the feces. Beginning on postinoculation day (PID) 10, 3 pups and 3 kittens were treated with milbemycin oxime (1.25 mg/kg of body weight, PO, q 12 h) for 10 days. Muscle biopsy specimens were taken from dogs and cats on PID 26 and 29, respectively. Mean numbers of larvae per gram of muscle were 30.3 in the control and 37.7 in the treated dogs. Mean numbers of larvae per gram of muscle in the control and treated cats were 318.7 and 89.3, respectively. Two dogs and 2 cats were removed from the study at that time. The remaining animals, 2 each of the control and milbemycin oxime-treated animals, were given albendazole (50 mg/kg, PO, q 12 h) for 7 days starting at PID 31 and 34 in dogs and cats, respectively. Muscle biopsy specimens were again taken at PID 46 and 49, for dogs and cats, respectively; mean numbers of larvae recovered from muscle were 0.6 for dogs and 13.5 for cats.

Effect of ivermectin on the control of ear mites (Psoroptes cuniculi) in naturally infested rabbits.

We examined the efficacy of ivermectin in the control of ear mites (Psoroptes cuniculi) in rabbits. The study involved 40 female and 35 male rabbits that were known to be naturally infested with ear mites. After a period of acclimation to the animal care facilities, the rabbits were ranked on the visual appearance of any ear lesion and the number of mites on glycerin-dipped ear swabs. The rabbits were then randomly assigned to 1 of 4 treatment groups; vehicle only (group 1), 50 micrograms of ivermectin/kg of body weight (group 2), 100 micrograms of ivermectin/kg (group 3) and 200 micrograms of ivermectin/kg (group 4). The rabbits were treated by SC injections on day 0 and day 14 of the trial; thus, the total dose of ivermectin given to groups 1 through 4, was 0, 100, 200, or 400 micrograms/kg, respectively. The study ended 2 weeks after the last treatment. Ear lesions of the treated rabbits improved significantly (P less than 0.001). By 28 days after the first treatment, the mean number of mites on the ear swabs (both ears) was 57.5 for untreated rabbits and 9.1, 0.5, and 2.5, respectively, for rabbits in groups 2, 3, and 4. The mean number of mites recovered from the ears of the untreated rabbits at necropsy was 24,297. For groups 2, 3, and 4, the mean number of mites recovered from the ears was 5,352, 96, and 96, respectively. The efficacy of treatment with a total dose of 100 micrograms/kg was 77.96%, with 200 micrograms/kg was 99.61%, and for 400 micrograms/kg was 99.61%.

Epidemiologic study of cadmium and lead in the hair of ceramists and dental personnel.

Ceramists may be exposed to heavy metal-containing dusts and vapors, especially when working with colored glazes. Because cadmium- and lead-containing glazes are commonly used, an epidemiologic study of the hair content of these metals among 70 ceramists in central New York was conducted. A comparably aged group of 75 dentists and orthodontists in the same geographic area was used as the control cohort. The median levels of both metals in the hair of the ceramists were significantly higher than those among the dental personnel. Most variables, including work habits and elements of the occupational setting, showed no significant effects on the concentrations of cadmium and lead in ceramists' hair. However, those ceramists whose studios were ventilated showed significantly lower levels of both metals in their hair. The use of protective masks or respirators was associated with significantly higher levels of cadmium in the hair of ceramists. A review of the literature on the subject is presented and the health significance of the results is discussed.

Tissue deposition of polychlorinated biphenyls in cats fed Atlantic Ocean bluefish.

Bluefish (Pomatomus saltatrix), a very popular marine sport fish caught in Atlantic coastal waters, contain significant levels of polychlorinated biphenyls (PCBs). Since fish can be an appreciable portion of human and feline diets, a feeding study was conducted with cats fed exclusively bluefish for 86 days with determination of tissue concentrations of PCBs. The concentrations of PCBs in brain, liver, and fat were significantly higher (p = 0.01) in the fish-fed cats than in the control group using the Wilcoxon rank sum test. The highest PCB levels were in fat, the median concentrations being 48 and 0.61 ppm (dry weight) in the fish-fed and control cats, respectively. The significance of the results is discussed.

Sulfadiazine-associated obstructive nephropathy occurring in a patient with the acquired immunodeficiency syndrome.

A 45-year-old man with the Acquired Immunodeficiency Syndrome (AIDS) and CNS toxoplasmosis presented with acute renal failure, hematuria, and renal colic shortly after starting treatment with sulfadiazine. Ultrasound examination of his kidneys was suggestive of intraparenchymal crystallization of sulfadiazine. His renal failure and ultrasound findings rapidly resolved with alkaline hydration. On rechallenge with sulfadiazine, he again developed renal insufficiency and ultrasonic findings consistent with stones. The use of sulfadiazine in the treatment of CNS toxoplasmosis in AIDS patients should be monitored carefully with the recognition that this form of crystalline-induced acute renal failure can occur in a dehydrated patient.

Determination of acquired immunodeficiency syndrome (AIDS) after renal transplantation.

Diagnosing the acquired immunodeficiency syndrome (AIDS) in transplant recipients can be difficult due to the patient's medication-induced immunosuppressed state. We report two renal allograft recipients who acquired HIV infection at the time of transplantation and later went on to develop multiple opportunistic infections. Careful documentation of HIV antibody status of the donor and recipient, when available, the nature of immunosuppressive therapy used, the type of infections and their timing after transplantation, as well as the patient's absolute T4 lymphocyte count, T cell ratio, and B cell humoral response to infection were used as factors to distinguish between infection related to immunosuppressive therapy and that seen in HIV-induced immunodeficiency. Reduction in immunosuppressive therapy because of the HIV-related immunodeficiency state did not result in allograft rejection. Both patients died of their multiple infections. The determination of AIDS in the transplant recipient has both therapeutic and prognostic significance. This diagnosis should be considered when transplant patients develop unusual infections in relationship to their posttransplant course.